Global Warming

Study: Global warming began earlier than previously thought

Man-made global warming may have started a few decades earlier than scientists previously figured, a new study suggests.

Instead of the late 1800s, a slight almost imperceptible warming can now be tracked to around 1850 in North America, Europe and Asia, according to a new study based on coral, microscopic organisms, ice cores, cave samples, tree rings and computer simulations.

And that happened when heat-trapping gases from burning fossil fuels were tiny compared with now, which means “the speed at which the climate responds to even a small change in greenhouse gases appears to be quite fast,” said study lead author Nerilie Abram, a paleoclimate scientist at the Australian National University. From about 1850 to 1880, Earth probably warmed around a third of a degree Fahrenheit. Still, that pales with about nine-tenths of a degree in the last 30 years or so.

Determining when warming started is more than just a historical question. Early heating could mean either a worse future climate than previously predicted if heat trapping gases aren’t controlled or, more optimistically, faster recovery by Earth if international efforts to cut greenhouse gases succeed.